Blown bulb causing parasitic drain?

[slim95x]

Just like the title says, can a blown headlight bulb cause parasitic battery drain? Or does it have nothing to do with it?

[tortoise2]

Previous context.

[oldgeek]

Bulb wont do it, most likely the alarm system. They are notorious for causing problems.

[slim95x]

I also thought its the alarm, but tried disconnecting it and measuring the draw, its the same. Im getting a constant draw of around 0,5a which kills the battery overnight. Already changed the rectifier, checked the fuses, checked the stator, the battery is being charged when the scooter is running. Cleaned the ground lead on the frame, just in case there was any problems with it. Battery leads look good too, maybe the negative lead had a tiny bit of corrosion on it, but i cleaned it off. The negative lead is brand new, since the old one was corroded beyond repair, so i changed it. Also, how do you keep the negative terminal from corroding, or is it just by constantly monitoring and cleaning it?

[lilpinny]

It wouldn't be the bulb. A blown bulb is an open circuit.

Alarms don't use much juice at all to run. They do draw off your battery but it's using just enough juice to flash that LED, which is next to nothing, certainly not half an amp.

[SMALL CC TEK]

Does that alarm have the electric start function ? That can kill a wiring harness fast !

[slim95x]

Yes, it does have the electric start function. The previous owner had a similar chinese alarm in it too, but i had to change it since he lost the remote from it. The negative lead was so gone, that i had to change around 6 inches of it. So what then? Get rid of the alarm, re-do the negative lead, and just use a regular brake disc lock?

[GrumpyUnk]

Remote start/alarm combinations use current. The remote start is essentially a radio receiver looking for a radio signal that it can pass over to the alarm circuit for decoding and matching, and then either providing power/ground to the starter relay, or ignoring the signal. Turn on a transistor radio(if you can find one) and figure your remote start will use a similar amount of power. Decode circuit to recognize the particular signal from the remote also uses power.
I have two brand-new alarms still in the box, want to buy one? They come with 9-volt battery and two remotes.

The battery cable that corrodes is either drenched with battery acid from a previous battery that outgassed when charged along with a potential acid/electrolyte spill, or the current battery that produces gas when being charged. If the charging system is too aggressive, it can cause outgassing, and produce a small cloud of corrosive gas inside the battery box.
Clean the ground cable with a mixture of hot water and baking soda. Stir in the baking soda until it dissolves. Drizzle drool or otherwise apply the soda/water mix to the cable and battery box. Where the mixture meets a surface/wire with acid on it, bubbles will form as the acid is neutralized. Wiping the top of the battery with a rag wetted in the solution can neutralize surface acid. Using an almost-sopping rag wetted with the solution on the battery terminals can clean them and lessen corrosion. You can dip the cables in the solution without negative effect. Wipe everything 'neutralized' with a rag/cloth dampened with tapwater.
Any thing that fizzes when it comes into contact with the baking soda solution should be repeatedly wiped/washed/drizzled with the solution until it no longer fizzes. Do NOT let the solution get inside the battery itself, or it will ruin the battery or at least reduce its capacity.
Once the cables are neutralized, flushed, and have dried completely, you can coat the bare wire with Vaseline or grease. Either will help shield the conductor from acid and the atmosphere. Ground cables do not generally need insulators as they are at the same voltage potential as the chassis and other components(everything but the + terminal and all conductors attached to it).
tom

added:
The only way I have seen a blown bulb have any effect on the remainder of an electrical system was the case where the bulb had come free from the bulb base(bulb originally glued into the socket with 'something'), allowing the conductors to the filaments to twist together and short out the circuit.  Blew several fuses before figuring that one out.
tom

[slim95x]

So, cleaned everything, didnt see any fizzing, which is a positive sign i guess. Re-did the negative lead again (second time already), put some grease on it, hopefully it helps with the corrosion . Now, the elephant in the room - the goddamn battery drain . Tried disconnecting the alarm, and measuring draw, still the same, getting aroun 0,5A of constant drain. The ground on the frame was a bit loose, so i put a new connector, cleaned it, put a bit of grease and tightened it - looks good, but still the same, constant battery draw. How in the hell do i troubleshoot or fix this, cause its annoying as hell. . Or should i just cut the negative wire, extend it somewhere near the ignition key, and put a flip switch between it, so i can break the circuit without having to unscrew the battery cover and taking off the negative lead?

[FrankenMech]

Track down the drain by disconnecting stuff until you find it.

[GrumpyUnk]

One thing that can go bad, and have no visual sign is the voltage regulator. It is connected to the battery 24X7x365... and should have a protective diode to prevent battery discharge. If the diode fails, you can get 'backflow' from the battery to ground with no sign except a dead battery.
You can remove the front cover and disconnect the regulator easily. Perhaps touch the surface to see if there is any warmth that could be due to resistive heating. Replacement regulators are not expensive.
Another thing that eat juice without outward sign is a broken horn. If the internal contacts are immobile, it can stay connected and produce no sound. Last but not least are corroded brake switches which might not make enough contact to light the filament, but make enough to pass electricity. They will/do rust if your machine is parked outside subject to rainfall. Replacement switches of the same dubious quality as the originals can be purchased from FE web sites at low cost. Installing new switches and protecting them from the elements afterward would go far to insure your brake light comes on when you have to jam on the brakes... may prevent you from being squished between a couple of bumpers...
tom

[slim95x]

Voltage regulator was the first thing i changed, since i thought that was the culprit too. Maybe its the horn, but it seems like its working fine. The starter button is not working. Brake lights seem to work just fine, turn on every time the brake is applied, and no intermittent flashing that could show that the connection is bad. At this point honestly, i just feel like changing everything, including the brake switches, wiring harness and the start button altogether. In theory that should get rid of any electrical problems?

[GrumpyUnk]

Connect your meter in series from the - terminal to ground. If it is reading 500ma, start disconnecting 'things'. An alarm will use amps, as will a remote start. A corroded brake switch could be sending some voltage to the brake light, not enough to be visible/glowing, but enough to eat a battery over time. Unlikely, but a starter relay that partially hangs could be sending power to the starter motor. Again, not enough to make the motor turn, but enough to drain the battery over time.
I mentioned the rectifier/regulator previously as it sits with solid state electronics between the battery and ground, and between the battery and '12v power consumers' in the system. The fuel gauge, and some other lights use rectified/regulated 12V. If the regulator is doofy, it could be leaking voltage. Try disconnected and see.
I more suspect the alarm and remote starter type items. If you have a Taotao, some remotes integrate right into the wiring snap-snap. To disable the alarm/remote you must disconnect it from the harness, and jumper some terminals in the 'alarn socket'. One will enable the 'kill' function of the ignition switch, the other enable 12v power. Look at the wiring schematics.
tom